Reliable ground source heat pump wanted

Hello,
our new building (approx. 6kW) will be heated with geothermal energy. I had initially thought of Nibe, AIT, or Tecalor. The architect's first contact is installing Buderus. Is Buderus also okay in the geothermal sector? Maybe even equivalent?
Finding independent advice is unfortunately difficult - every plumbing company has its favorite. Energy consultants drop out at the latest when it comes to choosing the manufacturer.
Or how did you end up with your heat pump?
Regards, burgerking

For us, this was handled through the property developer. If you are building without one, I would leave the selection of a good plumbing company to them. As I understand it, heat pumps involve little complex technology – compressors etc. are not really rocket science, so there will hardly be any fundamental differences (cf. e.g. refrigerator).

What is more important to me are the aspects of warranty, maintenance, local/quick service. And those depend more on the installer or manufacturer. The pump just has to work...

In my opinion, it also makes no sense to choose a pump yourself and then have the plumbing company familiarize themselves with it. They need to have experience with "their" pumps.

Yes, that's what I meant too. "My" installer simply has to have the pump and the associated control for it. I just wonder why so few Buderus devices appear in the "Wärmepumpen-verbrauchsdatenbank". It doesn't have to mean anything, but it does confuse me....

Because it is not so easy to compare it with a refrigerator. Of course, if you do not want to deal with the subject yourself, you primarily need a heating system that the trusted heating technician is familiar with. But you can also choose the technician based on who knows the heat pump you want to have. Or you can familiarize yourself with the topic a bit to support the heating technicians in case of problems. Because the basic technology or principle is always the same. Only the control behind it is different. For example, with the Nibe, which I also chose.